hvanflee

Just wondering if a backyard mechanic like myself can take out and reinstall a P7100 injector pump, or do I need to have a diesel shop do it?

Can the injector pump be worked on by a backyard mechanic?

The reason I ask is I have one cylinder that is not firing. I have checked the injector and the fuel lines. I think my injector pump needs some work. Before I do anything drastic I will have a piston pressure test done.

Thanks,
Howard

DieselDaze

It can probably be taken off and installed by a "BackYard Mechanic".
However, as I understand it, working on the P pumps takes some special equipment to calibrate the internals of the pump.

Rich

MnTom

This is probably going to sound dumb, but did you check the delivery valve on the pump? Is it possible that the pump is functioning like it should? Before I went ahead and pulled the pump I would check everything that I could. The next step I would take is a compression test and see what happens. Is there no fuel getting to the cylinder that is not firing? Once you find that out then you know which direction to go.
Keep us informed
Tom

hvanflee

Rich, thanks for you input.

Good suggestions Tom, after I had the injector checked I had to bleed the hole system, I was getting fuel to all 6 injectors, that does not mean there was enough pressure to pop the injector.

Tell me more about this delivery valve. Is there one for each injector? is it in the injector pump and can I check it myself? Next question is how do I check the delivery valve?

Thanks for your help,
Howard

MnTom

On the top of the pump there are 6 delivery valves. They are the things that are between the actual pump itself and the fuel lines. If I knew how I would post a picture so you cold see them. I think I would try to switch the valve from the dead cylinder with another to eliminate the valve as the culprit. You are supposed to use a special socket to remove them, but a pair of "vicegrips" do work. Just make sure that you keep track of the copper gaskets and such. ABOVE ALL ELSE KEEP IT CLEAN!!! Atleast then you will know if it is the pump or not.

hvanflee

Thanks Tom,
This is a great idea, I know exactly what you are talking about now. If the valve is bad will it deliver fuel to the injector at a low pressure or will it not deliver any fuel?

I will try an switch two valves and see what I get.

I went back and reread the other topic stuff I started in the help section, I now know what you were trying to tell me. I thought you were talking about the injector as the delivery valve. Sometimes I am so dumb

MnTom

Naw, y'ain't dumb............... Just sometimes we get somthin' in our heads that we can't get out . I just went back and reread that you say you are getting fuel to each injector. Would it be possible to pull the injectors and have them tested? Now might be the time to look into upgrading them.
Anyhow, Keep us informed.
Tom

hvanflee

I did have the one injector (#6), on the piston that was not warming up, tested. It tested to be just fine. Would you say that the delivery valve is not the problem if fuel is getting to the injector?

Could fuel be getting to the injector through the return line?

MnTom

Boy. the more I read the more expensive this sounds. I am beginning to think that the fuel system may be fine. Since you had that injector tested and it was ok I guess a compression test is next. I think you may find that you are going to be pulling the head and hopefully that is all you need to do. Is there ANY differant sounds such as a slight intermittant knock? I am beginning to wonder if there isn't something more serious going on. I understand that if the cooling nozzle is plugged or fell out you may not know for a while until you work the engine some and then score a piston or worse. I am not trying to scare you, but I am just throwng ideas at you. If I think of anything else I will let you know.
Tom

Mostwanted

congratulations!!

You upgraded from back yard to shade tree mechanic ;D.

MnTom

Who, me or hvanflee???????????

Mostwanted

hvanflee

Superduty12v

The delivery valve is a one-way check valve. If it is not working then the inj pump will pump the diesel up through the injector line but it will come right back down with the plunger if the vavle doesn't shut. so your pump could be fine as well as your injcr's.

98rammer

yes, you can do it in your yard...i put my marine pump on in my yard (it even sprinkled here and there).

yep, the delivery valve helps to control the fuel "waves" inside the fuel lines to prevent secondary/unwated injections from a "wave" going back to the injector (nozzle really) and injecting more fuel.

Tom

Extreme Diesel

I have taken my pump on/off a couple of times. Make sure you get the tools to time it though.